JP3805610B2 - Closed group communication method and communication terminal device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a closed group communication method and a communication terminal apparatus, and more particularly to a group communication method and a communication terminal apparatus in a relatively flexible closed communication network constructed by unspecified communication terminals.
[0002]
[Prior art]
A closed communication network is a communication network that can communicate only between specific communication terminals forming a group. The closed communication network can be constructed by, for example, connecting a plurality of communication terminals with a dedicated line and physically ensuring the closed property. In addition, a closed communication network can also be constructed by using user authentication, terminal device authentication, information encryption, etc., and virtualizing the communication network between communication terminals of a specific group. In such a closed communication network, each communication terminal can perform group communication by multicasting information to each other.
[0003]
In the wireless communication technology, for example, Japanese Patent Application Laid-Open No. 10-23028 discloses a method of constructing a closed communication network for an electronic conference system between a plurality of wireless terminals and performing group communication. In the invention of the above publication, an identifier list of terminals that are members of group communication is prepared in advance in a specific terminal, and when the group communication is started, the specific terminal sends the identifier list of member terminals to the broadcast message. Send with. Upon receiving the message, each terminal determines whether or not its own identifier is registered in the member identifier list, and if it is registered, notifies the specific terminal of its own address. The specific terminal creates an address list of the member terminals based on the received terminal address and distributes it to each member terminal. Thereby, each member terminal can acquire the addresses of all other member terminals, and group communication between member terminals becomes possible.
[0004]
[Problems to be solved by the invention]
In the group communication method described in the above publication, it is necessary to determine in advance member terminals that can participate in group communication and register the identifier of the member terminal in a specific communication terminal. Further, in group communication, it is necessary to call start of group communication from a specific terminal provided with an identifier list of member terminals to other member terminals, and it is not possible to call start of group communication from any member terminal.
[0005]
However, as a mode of use of group communication, for example, for the purpose of exchanging information for electronic conferences and entertainment purposes, the start of group communication is called from an arbitrary terminal device to an unspecified number of communication terminals present at the site. There is a case where it is desired to form a closed communication network with a terminal device that responds to a call and to easily hold a group communication. Further, when group communication is performed between a plurality of unspecified communication terminals, each terminal autonomously recognizes a member of the group (communication terminal) and may want to construct a flexible closed communication network.
[0006]
An object of the present invention is to provide a group communication method that can autonomously construct a closed communication network among a plurality of unspecified communication terminals.
Another object of the present invention is to provide a communication terminal device capable of joining and leaving a closed communication network composed of a plurality of unspecified communication terminals.
[0007]
[Means for Solving the Problems]
To achieve the above object, the group communication method of the present invention broadcasts an interrogation message including group identification information from an arbitrary first communication terminal to an unspecified number of communication terminals; The communication terminal receives a response message including the group identification information broadcast from another communication terminal, and responds within a predetermined time after the first communication terminal and the interrogation message are transmitted. A closed communication network is formed by at least one communication terminal that has transmitted the message, and group communication is performed by a communication message using the group identification information.
[0008]
More specifically, in the group communication method of the present invention, the address of the transmission source terminal of the response message received within a predetermined time after the first communication terminal transmits the challenge message corresponds to the group identifier. Stored as a group constituent terminal, a control message indicating the start of group communication is transmitted to the group constituent terminal at a predetermined timing.
[0009]
In a preferred embodiment of the present invention, prior to transmission of a control message indicating the start of group communication, the first communication terminal includes a step of notifying the group constituent terminal of an encryption key to be used for group communication. In addition, information indicating whether or not to disclose group communication is set in the interrogation message, and when the group communication is disclosed, a newly established terminal of the closed communication network formed in the initial state is newly added. The scale of the closed communication network is flexibly changed by executing a control procedure for adding a group constituent terminal with participating communication terminals.
[0010]
A communication terminal device according to the present invention includes a transmission / reception circuit for transmitting / receiving a communication message, a display device, an input device operated by a user, a storage unit storing a connection control program for controlling transmission / reception of the communication message, and A processor for executing a connection control program,
The processor broadcasts an interrogation message including group identification information to an unspecified number of communication terminals in response to user input from an input device, and a response message transmission source terminal received by the transmission / reception circuit. Control operation to store an address, form a group with a transmission terminal of a response message received within a predetermined time after transmitting the interrogation message, and perform group communication using the group identification information It is characterized by doing.
[0011]
Another feature of the communication terminal device of the present invention is that, when a call message from another terminal device is received by the transmission / reception circuit, the processor displays group type information included in the call message on the display device, A response message including the group identification information is broadcast in response to a user input from an input device.
With the above-described configuration, the communication terminal device of the present invention can autonomously recognize a group configuration terminal with an unspecified terminal to construct a closed communication network and perform group communication.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows an embodiment of a communication terminal apparatus according to the present invention that constructs a closed communication network and performs group communication with other terminals.
The communication terminal device 1 is a wireless terminal compatible with the Bluetooth specification having a relatively short communication distance of about several tens of meters, for example. The Bluetooth specification is disclosed in "Specification of the Bluetooth System Version 1.0 B" (Dec. 1st 1999, http://www.bluetooth.com).
[0013]
The wireless terminal 1 includes a memory 2 for storing control information and a control program, a transmission / reception circuit (Bluetooth Radio module) 3 for performing wireless modulation / demodulation of transmission / reception data, a console device 4, a console interface unit 5, a processor (CPU) ) 6.
[0014]
The memory 2 includes, as control software, a Bluetooth core protocol processing unit 21 that performs transmission / reception control, a Telephony Control protocol processing unit 22 that performs communication control by setting a communication connection, terminal identification (Authentication), and A security manager processing unit 23 having a service authorization function is provided. In the wireless terminal 1 of the present invention, the memory 2 further controls connection to form a closed communication network for group communication (hereinafter referred to as CUG (Closed Users Group)) between a plurality of arbitrary communication terminals. The processing part 24 and the member list part 25 for memorize | storing the management information regarding a CUG structure terminal are provided.
[0015]
FIG. 3 shows a closed communication network (CUG) composed of a plurality of wireless terminals 1 (1A, 1B, 1C,...) Constructed according to the present invention.
Each wireless terminal 1 creates a communication message in which control information such as, for example, a message type, a destination terminal address, and a group identifier is added to user information, and transmits the communication message through a broadcast channel. When each wireless terminal receives a transmission message from another terminal through a broadcast channel, whether the received message is a message addressed to itself or not based on control information such as a message type, a destination terminal address, and a group identifier given to the received message. The message addressed to the terminal is taken in, and other messages are discarded.
[0016]
That is, in the present invention, each wireless terminal 1 forming the CUG sends a message with a message type indicating group communication data and a group identifier of the CUG on the broadcast channel, and only the CUG configuring terminal By capturing the message, multicast communication 7 (7A, 7B, 7C,...) Of messages between CUG-configured terminals is enabled. Each wireless terminal encrypts a specific information part of the transmission message, for example, user information and specific control information, using an encryption key unique to each CUG, and decrypts the encrypted information only to the CUG configuring terminal. If the key is distributed, it is possible to realize group communication with high closedness that prevents interception of a message by a terminal other than the CUG configuring terminal.
[0017]
FIG. 4 shows a schematic processing phase in the connection control processing unit 24.
The new connection phase 10 is a phase for joining the wireless terminal 1 to the closed communication network (CUG). In this phase, a new CUG is created by calling from the wireless terminal 1 to another unspecified wireless terminal, Alternatively, a control operation for participation in an existing CUG is performed according to a participation request from the wireless terminal 1.
[0018]
The communication phase 11 is a phase for the wireless terminal 1 to perform closed group communication. In an embodiment to be described later, each CUG constituent terminal multicasts an encrypted message in the communication phase 11. In order to increase confidentiality, the encryption key is changed at random timing (keep alive processing).
[0019]
The addition phase 12 is a phase for adding another wireless terminal to the CUG to which the own terminal belongs. In the add phase 12, each terminal operating in the communication phase 11 receives a request for joining a CUG to which the terminal is subscribed from a new terminal, or calls on another terminal to join the CUG. This is executed when a participation response is received from a new terminal.
[0020]
The leaving phase 13 is a phase for deleting the management information of the leaving terminal from the member list part 25 of the CUG when any other terminal leaves the CUG. In addition to the wireless terminal that has transmitted the leave notification, each terminal constituting the CUG considers, for example, a wireless terminal that has not returned a response to an encryption key change call (keep-alive request) as a leaving terminal. The management information is deleted from the member list part 25 of the CUG.
[0021]
The cancellation phase 14 is a phase for deleting the management information of the leaving CUG from the member list part 25 of the CUG when the own terminal leaves the CUG. When leaving the CUG, each wireless terminal 1 transmits a leave notification to other terminals constituting the corresponding CUG, and deletes the management information related to the CUG from the member list unit 25. In the above-described leaving phase 13, when the management data of other leaving terminals is deleted from the member list unit 25, the CUG is canceled even when the CUG joining terminal becomes only the own terminal.
[0022]
FIG. 5 shows an example of various management lists formed in the member list section 25.
In the member list section 25, for example, four management lists are formed: a provisional group list 250A, a provisional terminal list 260A, a group list 250B, and a terminal list 260B.
The provisional group list 250A indicates management information related to a CUG that is being newly formed, and the provisional terminal list 260A is a CUG configuration terminal registered in the provisional group list 250A, that is, a wireless terminal that has called for formation of the CUG, The management information regarding the wireless terminal which has announced the subscription to the CUG is shown.
[0023]
The connection control processing unit 24 of each wireless terminal 1 monitors an interrogation message for forming a new CUG issued by another terminal and a response message from the other terminal. When an interrogation message for forming a new CUG is received, a management information entry related to the new CUG is registered in the temporary group list 250A. Each entry in the temporary group list 250A includes, for example, a newly generated CUG group identifier (hereinafter referred to as a temporary group identifier) 251A, a group type 252A of the CUG, and a pointer address of the temporary terminal list 260A corresponding to the CUG. 253A. As the group type 252A, for example, a communication purpose in the CUG, a representative name of the CUG, or the like is used.
[0024]
The provisional terminal list 260A includes, as management information of CUG configuration terminals, a user name 261A and a terminal address 262A extracted from a call message for forming a CUG, and a user name 261A and a terminal extracted from a response message to the call. Address 262A is registered. In each entry, information indicating the attribute of each member is registered as user information 263A.
The contents of the provisional group list 250A are displayed on the console screen at the time when the call message is received or in response to a request from the user, and when the user identifies any entry from the displayed provisional group list 250A, The contents of the provisional terminal list 260A corresponding to this are displayed on the console screen.
[0025]
The group list 250B indicates management information related to the CUG that the user (wireless terminal 1) has subscribed to, and the terminal list 260B indicates management information related to the constituent terminals of each CUG registered in the group list 250B.
Each entry of the group list 250B includes a CUG group identifier 251B, a CUG group type 252B, an encryption key 254B used in the CUG, and a pointer address 253B of the terminal list 260B corresponding to the CUG. .
Each entry of the terminal list 260B includes a user name 261A, a terminal address 262B, user information 263B, and a reception state 264B from each terminal that constitute each CUG. In the reception state 264B, ON is registered when a keep-alive request (encryption key change call), which will be described later, or a response is received from the corresponding terminal.
[0026]
Each wireless terminal 1 registers a terminal address registered in the terminal list 260B for the subscribed CUG as a connection-permitted terminal in the security manager processing unit 23, thereby allowing a point-to-point (P-P) from the corresponding terminal. When a connection setting request is received, a connection is established.
[0027]
FIG. 6 shows the relationship between the CUG control keys prepared in the console device 4 of the mobile terminal 1 and the display contents. The console device 4 includes a connection input key 41, a cancellation input key 42, an additional input key 43, and a display key 52 as CUG control keys. These control keys may be in the form of icons displayed on the console screen.
The connection input key 41 is used to cause the connection control processing unit 24 to start the process of the new connection phase 10. When the connection input key 41 is selected, the console device 4 is registered in the provisional group list 250A. A menu screen including a CUG option 44 (44A, 44B, 44C...) Indicating the contents of the group identifier 251A and group type 252B of each CUG and a new CUG option 45 is displayed.
[0028]
When the user selects any of the CUG choices 44, the terminal user name 261A, terminal address 262A, and user information 263A registered in the provisional terminal list 260A of the selected CUG are displayed on the console screen as the terminal user name 48 and the terminal, respectively. A member list having an address 49 and user information 50 is displayed. When the user selects the connection input key 41 in this state, connection processing for the selected CUG is executed. When the user selects the new CUG option 45, a group type input box 51 is displayed, and an input of the group type is accepted from the user. When the user selects the connection input key 41 after inputting the group type, a process for forming a new CUG is executed, and a message for inviting participation in the new CUG is multicast. Each time a response message to the challenge is received from another terminal, the terminal of the wireless terminal that has expressed participation in the new CUG (that is, the wireless terminal registered in the provisional terminal list 260A corresponding to the CUG) A user name 48, a terminal address 49, and user information 50 are displayed.
[0029]
The leave input key 42 is an input key for causing the connection control processing unit 24 to start the process of the cancellation phase 14. When the leave input key 42 is input, the console device 4 indicates the contents of the group identifier 251B and the group type 252B of the CUG registered in the group list 250B, that is, the CUG in which the wireless terminal 1 is currently participating. A menu screen is displayed including CUG options 46 (46A, 46B,...). When the user selects one of the options from the menu, a message for notifying the selected CUG configuring terminal of the withdrawal of the terminal is transmitted by multicast, and the entry regarding the leaving CUG is deleted from the group list 250B. The As the entry is deleted, the terminal list 260B corresponding to the leaving CUG is also deleted from the member list unit 25.
[0030]
The additional input key 43 is an input key for causing the connection control processing unit 24 to start processing in the additional phase 12 or the new connection phase 11. When the additional input key 43 is input, the console device 4 displays a terminal address input box 47 for specifying a partner terminal that requests connection to the same CUG. When the user inputs a terminal address in the terminal address input box 47, a message requesting connection to the same CUG as the own terminal is transmitted to the wireless terminal having the address.
[0031]
The display key 52 is an input key for displaying management information related to the CUG to which the wireless terminal 1 is currently participating or belongs. When the display key 52 is input, a menu screen appears on the console device 4, and options 46 (46A, 46B,...) Indicating the contents of the CUG group identifier 251B and group type 252B registered in the group list 250B are displayed. Is displayed. When the user selects any one of the options 46 in the menu, the terminal device name 261B, the terminal address 262B, the user information 263B, and the reception selection registered in the terminal list 260B corresponding to the selected CUG are stored in the console device 4. The contents of the field 264B are displayed as a terminal user name 53, a terminal address 54, user information 55, and a reception selection field 56, respectively. The reception selection field 56 is a field for designating whether or not to receive a received message from each CUG constituent terminal, and a check mark is normally set as a default value. If the user wants to discard the received message for a specific terminal, the user may delete the check mark attached to the reception selection field 56 of the specific terminal. When the check mark is deleted, the corresponding reception status field 264B of the terminal list 260B is turned off.
[0032]
Each time a user message is received, the wireless terminal 1 refers to the terminal list 260B. If the reception status field 264B of the entry corresponding to the transmission terminal address of the reception message is in the OFF state, the reception message is discarded. However, among the received messages from the terminals whose reception status field 264B is in the OFF state, only messages including normal user information are discarded, and control messages are not subject to discarding.
[0033]
1 and FIGS. 7 to 9 show a processing sequence for group communication executed by each wireless terminal 1, and FIGS. 10 and 11 show formats of various messages used in the group communication of the present invention. Means the information part to be encrypted. Each message includes a message type code part 100A indicating a message type and a data part 100B including control data or user data, as indicated by a message 100.
[0034]
FIG. 1 shows a processing sequence when the wireless terminal 1 becomes a caller to form a new CUG and construct a closed communication network. This processing sequence is executed in the above-described new connection phase 10.
When the connection input key 41 is selected on the console device and the new CUG option 45 is selected on the selection menu, the wireless terminal 1A generates a temporary group identifier 251A, prompts the user to set the group type 252A, and sets the temporary group list A new CUG management information entry including the identifier and group type is registered in 250A. Thereafter, the wireless terminal 1A generates and broadcasts an interrogation message 101 for calling an unspecified number of wireless terminals to participate in the CUG.
[0035]
As shown in FIG. 10, the interrogation message 101 includes a message type code 101A indicating interrogation, a provisional group identifier 101B, a transmission terminal address 101C, and other wireless terminals other than the initial state member (configuration terminal). Includes a public / private flag 101D indicating a policy of whether or not to disclose the CUG, a group type 101E, and user information 101F indicating a user name of the transmission terminal. In the case of a Bluetooth terminal wireless terminal, a MAC address assigned to each terminal can be used as the transmission terminal address 101C. Further, as the provisional group identifier 101B, the address of the wireless terminal 1A that is the transmission source may be used.
[0036]
After transmitting the interrogation message 101, the wireless terminal 1A starts a timer A and waits for a response from another wireless terminal during a predetermined initial member confirmation period (T1).
[0037]
Each wireless terminal has a function of monitoring the challenge message 101 and a response message thereto and registering a new entry in the provisional group list 250A and provisional terminal list 260A when these messages are received.
[0038]
When receiving the call message 101, the wireless terminals 1B and 1C register new entries corresponding to the CUG indicated by the call message in the temporary group list 250A and the temporary terminal list 260A. The provisional group identifier 101B and group type 101E extracted from the challenge message 101 are set in the registration entry of the provisional group list 250A. In addition, the terminal address 101C extracted from the challenge message 101 and the user name indicated by the transmission terminal user information 101F are set in the registration entry of the provisional terminal list 260A. Upon receiving the call message 101, the wireless terminals 1B and 1C notify the user of the occurrence of a new CUG through the console screen and wait for a response input from the user.
[0039]
In the wireless terminals 1B and 1C, when the user selects the connection input key 41 and selects the CUG entry from the menu displayed on the console screen, the management information entry of the selected CUG in the provisional group list 250A and After the contents of the corresponding provisional terminal list 260A are moved to the group list 250B and the terminal list 260B, respectively, the response message 102 is broadcast.
As shown in FIG. 10, the response message 102 includes a message type code 102A indicating a response, a provisional group identifier 102B, a transmission terminal address 102C, a transmission terminal public key 102D, and transmission terminal user information 102E.
[0040]
The wireless terminals 1B and 1C monitor the response message 102 from another terminal to the above challenge message, and when receiving the response message 102 from another terminal, the transmission terminal address 102C and the transmission terminal extracted from each response message An entry including the user information 102E is generated and registered in the provisional terminal list 260A. In this manner, each time the wireless terminal 1 (1A, 1B, 1C) receives the challenge message 101 or the response message 102, the wireless terminal 1 (1A, 1B, 1C) updates the provisional terminal list 260A or the terminal list 260A to autonomously configure the constituent terminal list of the new CUG. Create it automatically. The entry registered in the provisional terminal list 260A and the contents of the terminal list 260A corresponding to the entry are automatically deleted when a predetermined time elapses after receiving the challenge message.
[0041]
When the initial member confirmation period (T1) has elapsed, the wireless terminal 1A that has become the caller of the new CUG sends the entry of the provisional group list 250A related to the new CUG and the contents of the provisional terminal list 260A corresponding thereto. Move to group list 250B and terminal list 260B, respectively.
[0042]
The wireless terminal 1A sets up a P-P connection with each wireless terminal constituting the new CUG. As described above, in each wireless terminal, for the terminal addresses registered in the terminal list 260B, the P-P connection permission registration is performed in the security manager processing unit 23. Therefore, the wireless terminals 1B and 1C are wireless terminals. A request for setting a P-P connection from 1A is accepted. The wireless terminal 1A transmits a distribution message 103 in which a common encryption key used in the new CUG is set to each terminal through a PP connection set between the wireless terminals 1B and 1C. The common encryption key distribution message 103 includes a message type code 103A indicating the distribution of the encryption key, a group identifier 103B, and a common encryption key 103C encrypted with the public key of the partner terminal.
[0043]
The wireless terminals 1B and 1C that have received the distribution message 103 decrypt the encrypted portion 103C of the received message using their respective secret encryption keys to obtain a common encryption key. The wireless terminals 1B and 1C register the common encryption key obtained by decryption in the group list 250B as the encryption key 254B. On the other hand, the wireless terminal 1A that has transmitted the distribution message 103 also registers the common encryption key transmitted by itself as the encryption key 254B in the group list 250B.
[0044]
After distributing the common encryption key, the wireless terminal 1A generates the encryption key switching message 104, multicasts it to the constituent terminals of the new CUG, and then proceeds to the communication phase 11. As shown in FIG. 10, the encryption key switch message 104 includes a switch message code 104A and a group identifier 104B encrypted with the common encryption key. Each wireless terminal 1B, 1C shifts to the communication phase 11 upon receiving the switching message 104, and performs group communication while encrypting / decrypting transmission / reception information with the encryption key.
[0045]
In the communication phase 11, the constituent terminals of the CUG communicate with each other by multicasting the user data message 105. The user data message 105 includes a message type code 105A indicating user data, a group identifier 105B, a transmission terminal address 105C, and user data 105D. Of these, the transmission terminal address 105C and the user data 105D are common encryption. Encrypted by key. Since the information encrypted by the common encryption key can be decrypted only by the CUG configuration terminal having the same common encryption key, each of the configuration terminals 1 (1A, 1B, 1C) of the CUG has a highly closed group communication. Can be performed.
[0046]
FIG. 7 shows a state in which the wireless terminal 1 (1A, 1B, 1C) performing group communication periodically checks the CUG constituent terminals in the communication phase 11 and periodically updates the terminal list 260B. The alive processing sequence is shown.
Each component terminal of the CUG has a keep alive timer (C), and each time the encryption key switching message 104 is received, a random value is set in the keep alive timer (C) and activated. When the keep alive timer times out, the wireless terminal 1B multicasts a keep alive request message 106 and waits for a response for a certain period (T3). As shown in FIG. 10, the keepalive message 106 includes a message type code 106A indicating a keepalive, a group identifier 106B, a transmission terminal address 106C, and transmission terminal user information 106D. The terminal address 106C and the transmission terminal user information 106D are encrypted with the common encryption key.
[0047]
Each wireless terminal (1A, 1C) that has received the keep alive message 106 multicasts a continuation message 107 for notifying the continuation of the group communication in its own terminal as a keep alive response. The continuation message 107 includes a message type code 107A indicating a continuation message, a group identifier 107B, a transmission terminal address 107C, transmission terminal user information 107D, and a public key 107E of the transmission terminal, and includes a transmission terminal address 107C. The transmission terminal user information 107D and the public key 107E are encrypted with a common encryption key. The wireless terminals 1A and 1C that have received the continuation message 107 from another terminal stop their own keep-alive timer (C).
[0048]
Each component terminal of the CUG that has received the keep-alive message 106 or the continuation message 107 sets an ON flag indicating that communication is being continued in the reception status field 264B of the entry corresponding to the transmission terminal of the received message in the terminal list 260B, and receives the received message. Is not registered in the terminal list 260B, a new entry is additionally registered.
[0049]
The wireless terminal 1 </ b> B that has transmitted the keep-alive message 106 sets up a P-P connection with each wireless terminal that has returned the continuation message 107, and distributes a new common encryption key using the distribution message 103. Also, the wireless terminal 1B broadcasts the encryption key switching message 104 when a certain time (T3) has elapsed since the keep alive message 106 was transmitted. The switching message 104 includes a message type code 104A indicating a switching message and a group identifier 104B encrypted with a new common encryption key. The group identifier 104B may be changed to a new group identifier set by the wireless terminal 1B instead of the conventional identifier.
[0050]
When the group identifier is changed to a new identifier by the switching message 104, the CUG configuring terminal 1 (1A, 1B, 1C) registers this in the group list 250B. Each component terminal of the CUG deletes the entry for which the ON flag is not set in the reception state field 264B from the terminal list 260B at the time of transmission or reception of the switching message 104, and restarts the keep alive timer (C) with a random setting value. After starting, the CUG communication operation is continued. By issuing the switching message 104, each constituent terminal of the CUG applies a new common encryption key, and in some cases, continues group communication using a new group identifier.
[0051]
FIG. 8 shows a processing sequence when a new terminal 1D is added to a closed communication network including wireless terminals 1A, 1B, and 1C. These processes are executed in the addition phase 12 for the wireless terminals 1A, 1B, and 1C and in the new connection phase 10 for the new terminal 1D.
The process of connecting a new terminal to an existing CUG differs depending on the state of the public / private flag 101D of the challenge message 101 that is first broadcast when the CUG is configured. Here, a processing sequence in the case where the CUG is disclosed is shown.
[0052]
When the user selects the connection input key 41 and selects a new CUG 45 on the new terminal 1D, a new challenge message 101 is broadcast to an unspecified number of wireless terminals. The wireless terminals 1A, 1B, and 1C already in group communication transmit in response to the reception of the new challenge message 101 when the CUG is to be disclosed with the public / private flag 101D at the time of CUG configuration. A group notification message 108 is unicasted back to the original terminal 1D. As shown in FIG. 11, the group notification message 108 includes a message type code 108A indicating group notification, a destination terminal address (address of the terminal 1D) 108B, a group identifier 108C of the CUG in which the terminal is participating, The transmission terminal address 108D and the CUG group type 108E are included.
[0053]
When the terminal 1D receives the group notification message 108, the terminal 1D registers a new management information entry including the group identifier 108C and the group type 108E extracted from the received message in the temporary group list 250B. Display the contents. When a plurality of group notification messages having the same group identifier 108C are received, the subsequent messages are discarded, leaving the first received message.
[0054]
When the user of the terminal 1D selects the group identifier indicated by the group notification message 108 on the console screen and instructs the connection, the terminal 1D sends the transmission source of the group notification message 108 (in this case, the wireless terminal 1B). On the other hand, the participation confirmation message 109 is unicasted, the management information entry including the group identifier is moved from the temporary group list 250A to the group list 250B, and the address of the wireless terminal 1B is registered in the terminal list 260B.
[0055]
As shown in FIG. 11, the participation confirmation message 109 includes a message type code 109A indicating that it is a participation confirmation message, a destination terminal address (address of the wireless terminal 1B) 109B, and the group presented in the group notification message 108. It includes an identifier 109C, a transmission terminal address 109D, and a transmission terminal public key 109E.
[0056]
The wireless terminal 1B that has received the participation confirmation message 109A sets up a P-P connection with the new terminal 1D, and transmits a distribution message 103 indicating the common encryption key being used in the CUG. Further, an additional introduction message 110 indicating the address of the new terminal 1D is generated and multicast to each constituent terminal of the CUG. As shown in FIG. 11, the additional introduction message 110 includes a message type code 110A indicating additional introduction, a group identifier 110B, a new terminal address 110C, and new terminal user information 110D, and includes the new terminal address. 110C and user information 110D of the new terminal are encrypted with a common encryption key.
[0057]
Upon receiving the distribution message 103, the new terminal 1D registers the common encryption key in the group list 250B, and then waits for an acceptance confirmation message 111 transmitted from each constituent terminal of the CUG for a certain period (T5). On the other hand, the wireless terminal 1B that has transmitted the additional introduction message 110 and the other wireless terminals (1A, 1C) of the CUG that have received the additional introduction message 110 generate an acceptance confirmation message 111, respectively, and create a new terminal 1D. Unicast transmission. The acceptance confirmation message 111 includes a message type code 111A indicating acceptance confirmation, a destination terminal address (address of the wireless terminal 1D) 111B, a group identifier 111C, a transmission terminal address 111D, and user information 111E of the transmission terminal. including.
Among these items, the group identifier 111C, the transmission terminal address 111D, and the user information 111E are encrypted with a common encryption key. For example, a user name is set as the user information 111E.
The new terminal 1D registers the transmission terminal address 111D and user information 111E extracted from the acceptance confirmation message 111 received within a certain period (T5) in the terminal list 260B, and thereafter participates in group communication as a member of the CUG.
[0058]
FIG. 9 shows a processing sequence when the wireless terminal 1D during group communication leaves the CUG. These processes are executed in the elimination phase 14 in the leaving terminal 1D and in the leaving phase 13 in the other constituent terminals (1A, 1B, 1C) of the CUG.
When the user of the leaving terminal 1D selects the leaving input key 42 on the console screen and selects and inputs one of the group identifiers 46 displayed on the screen, the leaving terminal 1D receives the CUG having the selected group identifier. After the withdrawal notification message 112 is multicast transmitted to the constituent terminals, the management information entry having the group identifier is deleted from the group list 250B, and the corresponding terminal list 260B is deleted. In addition, the security manager processing unit 23 is notified, and permission for P-P connection regarding each constituent terminal of the CUG is deleted.
[0059]
As shown in FIG. 11, the leave notification message 112 includes a message type code 112A indicating a leave notification, a group identifier 112B, and a transmission terminal address 112C. Among these items, the transmission terminal address 112C is encrypted with the common encryption key.
[0060]
When the other constituent terminals (1A, 1B, 1C) of the CUG receive the leave notification message 112, they delete the address of the leave terminal 1D indicated by the received message from the terminal list 260B and notify the security manager processing unit, Cancel the PP connection permission of the leaving terminal 1D. Thereafter, each constituent terminal restarts the keep alive timer (C) with a random set value. As a result, the wireless terminal for which the keep-alive timer has timed out first starts the keep-alive process, and updates the encryption key used in the CUG.
[0061]
In each wireless terminal, if the terminal list 260B becomes empty as a result of deleting the leaving terminal from the terminal list 260B as described above or deleting the wireless terminal that does not respond in the keep-alive process from the terminal list 260B, The management information entry corresponding to the terminal list is deleted from the list 250B, and the group communication in the corresponding CUG is terminated. These processes are executed in the elimination phase 14.
[0062]
12 to 20 are flowcharts of programs provided in the connection control processing unit 24 of each wireless terminal 1 in order to execute the above processing sequence.
FIG. 12 shows a connection processing routine 100 to the closed communication network.
In the connection processing routine 100, a user event is monitored (S102). When a user event occurs, it is determined whether or not it is a connection instruction (S104). If it is not a connection instruction, a user event monitoring operation (S102). Return to, and wait for input of connection instructions. When the user instructs connection (selects the connection input key 41), it is determined whether or not a CUG management information entry is registered in the provisional group list 250A (S106). If the entry is registered, the registered CUG option 44 and the new CUG option 45 are displayed on the console device 4 to monitor the user event (S108).
[0063]
When a user event occurs, it is determined whether or not the user has selected a new CUG option 45 (S110). If the new CUG option 45 is selected, the automatically generated provisional group identifier and group type box 51 are input. The management information entry including the selected group identifier is registered in the temporary group list 250A (S112). Next, the interrogation message 101 is generated and broadcasted (S116), and then the timer A is started (S118). In step S119 of FIG. 13, a received message from another terminal is received for a certain time (T1). Monitor.
[0064]
When a message is received from another terminal, it is determined whether or not the received message is a group notification message 108 (S120). In the case of a group notification message, the group identifier and the group type are displayed on the console screen, and the group identifier and An entry including the group type is registered in the provisional group list 250A (S122). If the received message is the response message 102, an entry including the transmission terminal address and user information indicated by the response message 102 is registered in the provisional terminal list 260A (S124).
[0065]
Steps 119 to 124 are repeated until the timer A times out. When the timer A times out (S126), it is determined whether the group notification message 108 has been received (S128). If the group notification message 108 has been received, the user event is monitored (S130), and it is determined whether the new CUG option 45 has been selected (S132). When the user selects the new CUG option 45, the process proceeds to step S134. When the user selects the CUG option 44, an additional connection process (S300) described later with reference to FIG. 17 is executed.
[0066]
If the group notification message 108 has not been received or if the user has selected the new CUG option 45, the contents of the entry registered in the provisional group list 250A in step S112 are used to perform group communication with the new CUG. The contents of the provisional terminal list 260A corresponding to the group list 250B are moved to the terminal list 260B, and the address of each wireless terminal registered in the terminal list is registered for connection permission in the security manager processing unit 23 (S134). Next, a P-P connection is set up with each wireless terminal registered for connection permission, and an encryption key is distributed by the distribution message 103 (S136). If there is a terminal to which the encryption key cannot be distributed, the management information entry related to the terminal is deleted from the terminal list 260B. Thereafter, the encryption key switching message 104 is generated and multicast transmission is performed to each constituent terminal of the CUG (S138), and the process proceeds to the communication phase 200. The terminal 1A described in FIG. 1 executes the above processing sequence.
[0067]
Returning to FIG. 12, when the user selects a CUG option other than the new CUG option 45, that is, the CUG option registered in the provisional group list in step S110, the management information indicated by the CUG option in the provisional group list 250A. The entry is moved to the group list 250B, the contents of the provisional terminal list 260A corresponding to the entry are moved to the terminal list 260B, and the terminal address registered in the terminal list 260B is registered for connection permission in the security manager 23 (S142). Next, the response message 102 is generated and broadcasted (S144), and then the timer B is started. In step S148 of FIG. 14, a received message from another terminal is monitored for a certain time (T2).
[0068]
When the received message from another terminal is the response message 102, the transmission terminal address and user information of the response message are registered in the terminal list 260B, and the PP connection permission is given to the security manager processing unit 23 for the transmission terminal address. Register (S150). Next, it is determined whether or not the received message is the encryption key distribution message 103 (S152). If it is not the encryption key distribution message, it is determined whether or not the timer B has timed out (S164). If not timed out, the process returns to step S148 to continue monitoring the received message. If the timer B times out without receiving the encryption key distribution message, the currently registered entry is deleted from the group list 250B, and the corresponding terminal list 260B is deleted and registered in the terminal list. The connection permission in the security manager processing unit 23 is deleted for the terminal address (S162), and the connection process is terminated.
[0069]
If the received message is the encryption key distribution message 103 in step S152, the encryption key extracted from the received message is registered in the group list 250B (S153), and then the next received message is monitored (S154). When the message is received, it is determined whether or not the received message is the encryption key switching message 104 (S158). If the switching message 104 is received, the process proceeds to the communication phase 200. If the received message is not the switching message 104, it is determined whether or not the timer B has timed out (S160). If the received message has not timed out, monitoring of the received message is continued in step S154. If the timer B has timed out, the process proceeds to step S162, and after deleting the entry from the group list 250B, deleting the terminal list 260B, and deleting the terminal address connection permission in the security manager processing unit 23, the connection process is performed. Exit. The above processing corresponds to the operation of the terminals 1B and 1C described in FIG.
[0070]
FIG. 15 shows a flowchart of the keep alive processing routine S210.
In the keep alive process 210), a random time is set in the keep alive timer (C) (S212), and the timer is started (S214). Next, it waits for the keep-alive message 106 to be received (S216). When the keep-alive message is received, the keep-alive timer (C) is stopped and the continuation message 107 is multicast-transmitted to the CUG constituent terminals ( S218). Thereafter, the process waits for reception of the encryption key distribution message 103 (S220). If the encryption key distribution message 103 cannot be received within a certain period of time, the keep-alive process is terminated.
[0071]
If the encryption key distribution message 103 is received within a certain period of time, it waits for the encryption key switch message 104 to be received (S222). If the switch message 104 cannot be received, the keep alive process is terminated. If the switching message 104 is received within a certain period of time, the management information entry of the terminal that did not multicast the continuation message 107 in response to the keep-alive message 106 is deleted from the terminal list 260B, and the security for the terminal The manager processing unit 23 deletes the PP connection permission registration (S224), registers the new encryption key and the group identifier indicated by the encryption key distribution message 103 in the group list 250B (S226), and then returns to step S212. The above processing corresponds to the operation of the wireless terminals 1A and 1C described with reference to FIG.
[0072]
The reception of the keep-alive message 106 in step S216 is repeated until the keep-alive timer (C) times out (S228). When the keep-alive timer (C) times out, after executing the keep-alive request processing 230, The process returns to step S212.
[0073]
FIG. 16 shows a detailed flowchart of the keep-alive request process 230.
In the keep alive request processing 230, the keep alive message 106 is multicast transmitted (S232), and the encryption key is distributed by the encryption key distribution message 103 to the terminal that has returned the continuation message 107 in response to the message (S234). . For a terminal that has not responded to the keep-alive message 106 within a certain period of time, the management information entry is deleted from the terminal list 260B, and the PP connection permission in the security manager processing unit 23 is deleted (S236). .
[0074]
Next, the registration entry in the terminal list 260B is checked (S238). If there is a registration entry in the terminal list 260B, the group identifier and the encryption key are registered in the group list 250B (S240), and the CUG registered in the terminal list 260B is registered. The switch message 104 is multicast-transmitted to the constituent terminals (S242), and the process proceeds to step 212 in FIG. If no entry is registered in terminal list 260B in step S238, keep-alive processing 210 is terminated.
The above processing corresponds to the operation of the wireless terminal 1B described with reference to FIG.
[0075]
FIG. 17 shows a flowchart of an additional connection processing routine 300 to the closed communication network.
In the additional connection processing routine 300, the management information entry of the CUG selected by the user in step S132 of FIG. 13 is moved from the temporary group list 250A to the group list 250B, the temporary terminal list 260A corresponding to the CUG is moved to the terminal list 260B, For the terminal address registered in the terminal list, the P-P connection permission is registered in the security manager processing unit 23 (S302). Next, a participation confirmation message 109 is generated and returned to the wireless terminal that has transmitted the group notification message (S304), and the reception of the encryption key distribution message 103 is awaited (S306). If the encryption key distribution message cannot be received within a certain time (T4), the management information entry registered this time is deleted from the group list 250B, the corresponding terminal list 260B is deleted, and the terminal list 260B indicates For the CUG constituent terminals, the PP connection permission of the security manager processing unit 23 is deleted (S308), and then the connection process is terminated.
[0076]
When the encryption key distribution message 103 is received within a predetermined time (T4), the timer D is started (S310) and the received message is monitored. When the acceptance confirmation message 111 is received, an entry including the transmission terminal address of the received message and the user name indicated as the user information is registered in the terminal list 260B, and the terminal address is registered in the security manager processing unit 23. -P connection permission is registered (S312). The reception process of the acceptance confirmation message 111 is repeated until the timer D times out. When the timer D times out (S314), the process proceeds to the communication phase 200. The above processing corresponds to the operation of the new terminal 1D described with reference to FIG.
[0077]
FIG. 18 shows a flowchart of an acceptance processing routine 400 executed by the wireless terminal that accepts a new terminal in the CUG.
In the acceptance processing routine 400, the received message is monitored (S402). When the message is received, it is determined whether or not the received message is the challenge message 101 (S404). If it is not the challenge message 101, the process returns to step S402 to continue monitoring the received message. When the challenge message 101 is received, it is determined whether or not the CUG in which the terminal participates is disclosed (S406). If the CUG is not disclosed, the process returns to step S402. If the CUG is open to the public, the group notification message 108 is transmitted to the new terminal that is the transmission source of the challenge message 101 after a lapse of a randomly set time (S408) (S410). ), And waits for the participation confirmation message 109 from the terminal to be received (S412).
[0078]
When the participation confirmation message 109 is received, a P-P connection is set for the new terminal, and an encryption key to be used in the CUG is distributed by the encryption key distribution message 103 (S414). Next, the address of the new terminal is notified to the CUG constituent terminal by the additional introduction message 110 (S416), the management information entry of the new terminal is registered in the terminal list 260B, and the security manager processing unit for the new terminal address 23, connection permission is registered (S418). Thereafter, an acceptance confirmation message 111 is transmitted to the new terminal (S420), and the process proceeds to the communication phase 200.
The above processing corresponds to the operation of the terminal 1B described with reference to FIG.
[0079]
FIG. 19 shows a flowchart of the separation processing routine 500.
In the leaving process routine 500, the received message is monitored (S502), and it is waited for the leaving notification message 112 to be received (S504). When the withdrawal notification message 112 is received, the management information entry of the source terminal of the withdrawal notification message is deleted from the terminal list 260B, and the connection permission of the security manager processing unit 23 is deleted for the address of the terminal (S506). The number of entries remaining in the terminal list 260B is checked (S508). If there is a registered terminal in the terminal list, the keep-alive process 210 is executed, and then the process returns to step S502 to continue monitoring the received message. If the number of terminals registered in the terminal list 260B becomes zero as a result of deleting the entry of the leaving terminal, the CUG management information entry corresponding to the terminal list 260B is deleted from the group list 250B, and the process ends. The above processing corresponds to the operation of the terminals 1A, 1B, and 1C described with reference to FIG.
[0080]
FIG. 20 shows a flowchart of a cancellation processing routine 600 executed by the wireless terminal that has left the closed communication network.
In the cancellation processing routine 600, the user event is monitored (S602), and the process waits for the input of a leave instruction by operating the leave input key 43 (S604). When the leave instruction is input, the leave notification message 112 is multicast-transmitted to the CUG constituent terminal selected by the user on the menu screen (S606). Next, the management information entry of the leaving CUG is deleted from the group list 250B, the terminal list 260B corresponding to this is deleted, and the terminal address registered in the terminal list 260B is connected to the security manager processing unit 23. The permission is deleted (S608), and the process is terminated. The above processing corresponds to the operation of the leaving terminal 1D described with reference to FIG.
[0081]
FIG. 21 shows a processing sequence for causing a new terminal 1D to participate in a private CUG that is already in group communication as another embodiment of the additional connection processing.
In this embodiment, as a condition for the new terminal 1D to participate in the private CUG later, the user of the new terminal 1D knows at least one terminal address of the terminal group constituting the CUG, and the terminal Will be notified of their request for participation. Here, a processing sequence in the case where the user of the new terminal 1D knows the address of the wireless terminal 1B and requests additional participation from the wireless terminal 1B in group communication is shown.
[0082]
The new terminal 1D sets up a P-P connection with the known wireless terminal 1B, and transmits a participation request message 113. As shown in FIG. 11, the participation request message 113 includes a message type code 113A indicating participation request, a transmission terminal address 113B, a public key 113C of the transmission terminal, and user information 113D indicating, for example, a user name.
When the wireless terminal 1B receives the participation request message 113, the wireless terminal 1B distributes the encryption key currently used in the CUG to the new terminal 1D by the distribution message 103. The subsequent processing sequence is the same as in FIG.
[0083]
FIG. 22 shows a processing sequence in a case where the new terminal 1D is invited to join the new terminal 1D from the CUG constituent terminal side as a further embodiment of the additional connection process, and the new terminal 1D additionally participates in the CUG in response to this. Indicates.
When the user of the wireless terminal 1B participating in the CUG and performing group communication inputs the additional input key 43 on the console screen and inputs the address of the new terminal 1D in the terminal address input box 47, the wireless terminal 1B to the new terminal 1D A group notification message 108 is transmitted.
[0084]
When the new terminal 1D receives the group notification message 108, the new terminal 1D displays the group identifier and group type notified by the group notification message 108 on the console screen. When the user of the new terminal 1D selects the connection input key 41 and selects the group identifier, the participation confirmation message 109 is transmitted from the new terminal 1D to the wireless terminal 1B, and thereafter, the same processing sequence as in FIG. 8 is executed. Is done.
[0085]
FIG. 23 shows a flowchart of an interrogation connection processing routine 700 for realizing the additional connection shown in FIGS.
In the interrogation connection processing routine 700, a user event is monitored (S702), and the generation of an addition instruction is awaited (S702). When the user selects the additional input key 43 on the console screen and inputs a destination wireless terminal address in the address input box 47, the terminal is currently belonging to the CUG (during group communication) with reference to the group list 250B. It is determined whether or not (S706). If it belongs to the CUG, the process after step S410 of the acceptance process routine shown in FIG. 18 is executed. With the above processing sequence, the operation of the terminal 1B described with reference to FIG. 22 is executed.
[0086]
If the terminal itself does not belong to the CUG, a P-P connection is set up with the wireless terminal address input in the address input box 47, and a participation request message 113 is transmitted (S708). Next, it waits for the encryption key distribution message 103 to be received (S710). When the encryption key distribution message 103 is received, the management information entry including the CUG group identifier and the encryption key notified in the message is grouped. It registers in the list 250B, registers the terminal address which is the destination of the participation request message 113 in the corresponding terminal list 260B, and registers connection permission in the security manager processing unit 23 for this terminal address (S712). Thereafter, the processing after step S310 of the additional connection processing routine shown in FIG. 17 is executed. With the above processing sequence, the operation of the new terminal 1D described with reference to FIG. 21 is executed.
[0087]
FIG. 24 shows another embodiment of the acceptance processing routine 400.
In the acceptance processing routine 400, the received message is monitored (S 402), waits for the participation request message 113 to be received (S 421), and when the participation request message 113 is received, the message transmission source terminal is notified. The encryption key distribution message 103 is transmitted (S422), and the processing after step S416 of the acceptance processing routine shown in FIG. 18 is executed. With the above processing sequence, the operation of the terminal 1B described with reference to FIG. 21 is executed.
[0088]
FIG. 25 shows another embodiment of the additional connection processing routine 300.
In the additional connection processing routine 300, the received message is monitored (S316), waits for the group notification message 108 to be received (S318), and when the group notification message 108 is received, the additional connection processing shown in FIG. The process after step S302 of the routine is executed. With the above processing sequence, the operation of the new terminal 1D described with reference to FIG. 22 is executed.
[0089]
In the above embodiment, an example in which a CUG constituent terminal communicates user information and control information by multicast or unicast transmission of a message using a broadcast channel has been shown. A P-M (Point-to-Multipoint) connection set between constituent terminals may be used, and a P-P connection set between constituent terminals may be used instead of the unicast. When using a P-M connection or a P-P connection, each wireless terminal can limit a message transmission partner by selectively setting a connection with another wireless terminal constituting the CUG.
[0090]
For example, on the menu screen of the group list shown in FIG. 6, in addition to the reception selection field 56, a transmission destination selection field is also prepared. For terminals that do not have a check mark in the transmission destination selection field, It is also possible not to set a connection.
[0091]
FIG. 26 shows a network configuration in which an Internet terminal 1F is connected to a CUG composed of wireless terminals 1A, 1B, and 1C in group communication via an IP network 9 such as the Internet and an access point 8.
Since the message cannot be broadcast to an unspecified number of terminals on the IP network, the Internet terminal 1F cannot broadcast the challenge message 101 for connecting to the existing CUG. In such a case, in order to be able to accept a connection from an Internet terminal, for example, the address of the terminal representing the CUG is registered in the public group database 15 on the Internet together with the group identifier and the group type. The 1F may refer to the public group database 15 to select a CUG desired to participate, and transmit a participation request message 113 to the address of the representative terminal of the selected CUG. If the representative terminal is associated with the terminal 1B and the Internet terminal 1F is associated with the new terminal 1D, the Internet terminal 1F can be joined to the existing CUG according to the processing sequence shown in FIG.
[0092]
【The invention's effect】
As is clear from the above description, according to the present invention, an arbitrary terminal calls group formation by broadcasting group identification information to an unspecified number of terminals, and the terminal that has called and the terminal that has responded to it. And a closed communication network, and a group identifier (group address) is used to enable group communication between a plurality of terminals.
According to the present invention, the scale of the closed communication network can be flexibly changed by allowing the addition and removal of terminals from the initially formed closed communication network, and communication within the closed communication network can be performed. When encrypted communication is applied to, information exchange with high confidentiality can be performed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a sequence when a new closed communication network is configured by a plurality of terminals in the present invention.
FIG. 2 is a block diagram showing an embodiment of a communication terminal device according to the present invention.
FIG. 3 is a diagram showing an example of a closed communication network configured according to the present invention.
FIG. 4 is a diagram showing a schematic processing phase in a connection control unit 24 of a communication terminal device.
FIG. 5 is a diagram showing an example of various management lists formed in the member list section 25 of the communication terminal device.
FIG. 6 is a diagram showing an example of operation keys and display contents provided in the console device of the communication terminal device.
FIG. 7 is a diagram showing a sequence of keep alive processing in the present invention.
FIG. 8 is a diagram showing a processing sequence when a new terminal is added to an existing closed communication network in the present invention.
FIG. 9 is a diagram showing a processing sequence when a terminal in group communication leaves the closed communication network in the present invention.
FIG. 10 is a diagram showing a format of communication messages 100 to 107 used in the embodiment.
FIG. 11 is a diagram showing a format of communication messages 108 to 113 used in the embodiment.
FIG. 12 is a flowchart showing a part of a connection processing routine 100 provided in the connection control unit 24 of the communication terminal.
13 is a flowchart showing another part of the connection processing routine 100. FIG.
14 is a flowchart showing the remaining part of the connection processing routine 100. FIG.
FIG. 15 is a flowchart showing a keep alive processing routine 210 provided in the connection control unit 24;
FIG. 16 is a flowchart showing details of a keep-alive request process 230 in the keep-alive process routine 210;
FIG. 17 is a flowchart showing an additional connection processing routine 300 provided in the connection control unit 24;
18 is a flowchart showing an acceptance processing routine 400 provided in the connection control unit 24. FIG.
FIG. 19 is a flowchart showing a disconnection processing routine 500 provided in the connection control unit 24.
20 is a flowchart showing a cancellation processing routine 600 provided in the connection control unit 24. FIG.
FIG. 21 is a sequence diagram showing another embodiment of the additional connection process.
FIG. 22 is a sequence diagram showing still another embodiment of additional connection processing.
23 is a flowchart showing a call connection processing routine 700 provided in the connection control unit 24. FIG.
24 is a flowchart showing another embodiment of the acceptance processing routine 400. FIG.
FIG. 25 is a flowchart showing another embodiment of the additional connection processing routine 300;
FIG. 26 is a diagram showing an example of the configuration of a closed communication network that allows additional connection of Internet terminals.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Communication terminal device, 2 ... Memory, 3 ... Transmission / reception circuit, 4 ... Console apparatus,
5 ... console interface unit, 6 ... CPU, 8 ... access point,
9 ... Internet, 15 ... Public group database,
23 ... Security manager processing unit, 24 ... Connection control processing unit,
25 ... Member list part, 250A ... Temporary group list, 250B ... Group list, 260A ... Temporary terminal list, 260B ... Terminal list

Claims (9)

In a group communication method in which a plurality of communication terminals communicate by forming a closed communication network,
Each communication terminal receives a group formation challenge message broadcast from any other communication terminal;
A communication terminal that intends to join a group broadcasts a response message including group identification information indicated by the challenge message;
Each communication terminal has a step of storing a terminal address indicating a transmission source of the challenge message and the response message received from another communication terminal as an address of a group constituent terminal corresponding to the group identification information,
A closed communication network is formed by the communication terminal that has transmitted the interrogation message and the communication terminal that has transmitted a response message within a predetermined time after the interrogation message is transmitted, and the group identification information is used. A group communication method comprising performing group communication by a communication message.   The communication terminal that has received the group formation challenge message from another communication terminal displays the group type information indicated by the challenge message on the display screen, in response to an input operation indicating group participation from the terminal user, The group communication method according to claim 1, wherein a response message is broadcast.   When a notification message indicating group leaving is received from another communication terminal, the source terminal of the message is excluded from the group configuration terminal, and the group communication ends when there is no group configuration terminal other than the own terminal. The group communication method according to claim 1, wherein the group communication method is performed.   The interrogation message includes information indicating whether or not to disclose group communication, and when group communication is disclosed, a closed communication network configuration terminal formed in an initial state and a newly participating communication terminal; The group communication method according to claim 1, wherein a control procedure for adding a group constituent terminal is executed between the groups. In a communication terminal device that performs group communication with other communication terminals,
The group formation challenge message broadcast from any other communication terminal and the response message from the other communication terminal to the challenge message are monitored and associated with the group identification information indicated by the challenge message. A list generation unit for storing a source address of the challenge message and the response message in a group list as a terminal address of a group member;
Means for broadcasting a response message for participating in group communication by applying the group identification information indicated by the challenge message;
A communication terminal device, comprising: a communication network including another communication terminal stored as a member in the group list as a communication partner; and a means for transmitting and receiving a communication message including the group identification information. . Means for displaying the contents of the group list on a display screen upon receipt of the challenge message or in response to a request from a terminal user;
6. The communication terminal apparatus according to claim 5, wherein the response message is broadcast in response to a group join request from a terminal user input during the group list display. The challenge message includes group type information,
The list generation unit stores the group type information in the group list in association with the group identification information,
The communication terminal device according to claim 6, wherein a terminal user can perform an input operation of the group participation request with reference to the group type information displayed on the display screen. Each of the challenge message and the response message includes a transmission source user name,
The list generation unit stores the user name together with the terminal address in the group list,
The terminal user can perform an input operation indicating the group participation request with reference to the user name displayed as a constituent member on the display screen. Communication terminal device. The group list includes a provisional group list indicating a state before the terminal participates in group communication, a regular group list indicating a state after the terminal broadcasts a response message for participating in group communication, and Consists of
9. The communication terminal apparatus according to claim 5, wherein formation of the closed communication network and transmission / reception of communication messages are performed based on the regular group list.

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